The long term objective is to develop a new class of Continuous Positive Airway Pressure (CPAP) devices that in addition to treating OSA patients can conduct simultaneous cardiorespiratory measurements for improved therapy assessment. CPAP is by far the most common therapy for patients with Obstructive Sleep Apnea (OSA) with over 300,000 new therapies initiated each year. Unfortunately, once prescribed, CPAP treatment is not typically monitored. In order to properly assess symptoms, patients must be brought back to the lab for evaluation, which is expensive, inconvenient and has long waiting periods. Some of the more advanced CPAP machines can monitor patient's breathing pattern by measuring the airflow signal during the night. However, accurate patient assessment requires simultaneous evaluation of multiple cardiorespiratory information to confirm events such as Apnea, Hypopneas, Desaturations, and Cardiac function. Cardiorespiratory information can also help classify the origin of the event such as differentiating central from obstructive events. Research found that OSA patients, especially those with comorbidities, do suffer from unresolved nocturnal events that were not detected using current technologies and that additional therapy intervention was needed. Also, detailed efficacy data has been shown to actually improve patient compliance through fast intervention and encouraging feedback. We propose to develop a new CPAP device that can monitor EKG, chest effort, pulse oximetry, body position, and airflow. Monitoring of all parameters is expected to be intermittent warranted by weight gain, alcohol use, resurgence of OSA symptoms, or emergence of new complications. When monitoring is needed, patients simply wear a small wireless Chest Module and data is transmitted automatically into the CPAP, which is equipped with special data reception, storage capability and analysis algorithms. The CPAP automatically downloads the data to the doctor's office including raw waveforms and quantitative information such as AHI, desaturation profiles, and heart rate variability. The result is efficacy data that can be truly compared with original assessment done in the lab. The Chest Module can be easily recharged for multiple night recordings. We have successfully met and exceeded Phase I objectives. We developed and tested wireless hardwdare including the Chest Module and a CPAP interface. Testing was done on 3 volunteers. Additionally, we conducted a case study that showed unresolved significant nocturnal events during CPAP; events that would have gone undetected with current technology. We have assembled a team with excellent clinical and commercial expertise for this project. In Phase II, we will finish the design, fabricate 10 complete systems and test on 20 OSA patients to confirm performance, and ease of use. Comparison with current CPAP techniques and in-lab PSG will be done. [unreadable] [unreadable]